Geothermal resources are among the most secure renewables for reliable baseload energy production. Today the total installed capacity worldwide is around 15 GWe, with the USA, Philippines, Indonesia and Turkey leading the way.
Geothermal energy offers tremendous untapped potential ready to be exploited with modern and proven technologies. Moreover, this renewable source has some advantages that can further drive its growth. It is stable, versatile, efficient and reliable
Growing demand for power production from geothermal resources at medium-low temperatures has made the ORC, also known as “binary plant”, the preferred technology over flash steam solutions.
With the Radial Outflow Turbine technology, Exergy offers highly efficient, reliable and tailor-made geothermal binary plants and has a portfolio of over 470 MWe of geothermal power installed or under construction today.
Thanks to comprehensive experience with different geothermal resource and environment conditions in several countries worldwide, and with a wide array of power plants solutions and turbine sizes, we are able to offer high technical expertise to our customer and help them harness their full geothermal potential.
Exergy’s ORC systems can be applied in diverse resource conditions and plant configurations:
Binary geothermal power plants can feature multi-pressure-level cycle systems. This cycle configuration offers a significant increase in power output and cycle efficiency. Technologically advanced multi-pressure-level geothermal binary systems traditionally available on the market require at least one turbine per pressure level. The Exergy Radial Outflow Turbine, thanks to its unique single-disk and multi-stage configuration, allows multiple pressure level cycles to be expanded on a single-disk overhung turbine.
The geothermal fluid flows through the first sequence of HIGH pressure heat exchangers, transferring heat to the organic fluid. This organic fluid vaporizes and flows into the HIGH pressure turbine Inlet. Then the geothermal fluid flows through the second sequence of LOW pressure heat exchangers, vaporizing the organic fluid, which is then admitted into the LOW pressure turbine Inlet. The Exergy Radial Outflow Turbine (ROT), fed by HIGH and LOW pressure organic fluids, drives a generator to produce electrical power. The geothermal fluid is then re-injected back into the ground and the cycle continues.
In single flash steam power plant operation, a significant part of the total thermal capacity is lost in the liquid phase (brine). Combining an ORC with a single flash power plant is possible to safely and efficiently recover energy contained in the brine that would otherwise be wasted to generate additional electricity.
This solution can boost the efficiency of an existing geothermal installation by increasing the steam field rated electrical power output with no additional environmental impact.